I wish to share with you my experiences in using these two new ground breaking products, one superb HMC5883L breakout board and a new series of LCD displays from Jameco. I have to first tell you I have spent every waking hour in the past month diving head first into the triple axis magnetometer learing the significance of every byte of data and pouring over the graphs and data sheets on this very fine Honywell product.

Several manufacturers sell breakout boards for this tiny surface mount part, but let me tell you this - The Adafruit version is the only one with complete 5v interface circuitry built in, and the a killer $9 price too! I bought a handful of them and they work very well indeed.

Second, Jameco now sells a new line of LCD displays that are serial driven, have a awesome contrasty transreflective screen and are a fraction of the cost of anybody elses in this quality range. I'm using this LCD - a 20 x 4 model in the code below, and you can use the functions/drivers I have in this program to operate the display. You might
buy a handful of these as well. ;)

This is a triple axis magnetometer which uses three tiny magneto-resistive sensors, made of a nickel iron alloy called "permalloy". The chip mounts them as part of a bridge and includes a digitally selectable internal amp to select different field ranges. A 12 bit a/d converter sends all data out a two wire serial port using I2C format.

Description of the code below. The code is written as a continous loop that reads the magnetometer, sends the results to the display. I wrote everything up as a few separate functions to allow more flexibility in the applications. Our use for now is robot navigation.